The proposed project is centered on testing the hypothesis that "treponemzl components immunosuppress vis macrophage dysfunction involving early synthesis of prostaglandin (PGEZ), which in turn back regulates macrophage produced, interleukin II, I secretion. The proposed project will attempt to break treponemal immunosuppression by using the prostaglandin inhibitor indomethacin to minimize PGE2 synthesis in vivo. Experiments will focus on four specific areas including: 1) Interleukin I secretion by stimulated macrophages and II-2 effects on T-lymphocytes, 2) PGE2 Secretion by stimulated macrophages and blockage of secretion by indomethacin, 3) Trepohemicidzl activity of spleen cell preparations as evidenced by indomethacin, and 4) Immunization of rabbits with heated T. pallidum and indomethacin to restore normal immune functioning.